Brush cutter having locking mechanism for cutter guard

Abstract

A brush cutter device having a latch assembly for securing a movable cutter guard in a closed position when the brush cutter is tilted beyond a predetermined angle. The guard is combined with a side of the housing and movable between a closed position and an open position. A latch is combined with a portion of the housing and is capable of moving between a retracted position wherein the guard is able to move freely between its open position and its closed position and an engaged position wherein the latch prevents the guard from moving to its open position. Upon tilting the brush cutter beyond a certain angle, gravity acts on the latch causing it to move from its retracted position to its engaged position. The guard would move from its closed position to its open position upon tilting the brush cutter beyond a certain angle, however, the latch is moved beyond its pivot point before the guard moves beyond its pivot point to lock the guard in its closed position.

What is claimed is as follows: 
     
       1. A brush cutter comprising:
 a housing; 
 a cutting member combined with the housing; 
 a guard combined with the housing, the guard having an open position wherein the cutting member is exposed for cutting operations and a closed position wherein the cutting member is at least partially shielded by the guard; 
 a latch assembly having a latch movable between a retracted position wherein the guard is movable from the closed position to the open position and an engaged position wherein the latch prevents movement of the guard from the closed position to the open position; 
 wherein the latch has a latch pivot point and is configured to move from the retracted position to the engaged position when the housing is tilted beyond the latch pivot point. 
 
     
     
       2. The brush cutter of  claim 1  wherein the guard has a guard pivot point. 
     
     
       3. The brush cutter of  claim 2  wherein the latch pivot point is reached when the housing is tilted a first angle relative to a horizontal ground surface and the guard pivot point is reached when the housing is tilted a second angle relative to the horizontal ground surface, wherein the first angle is less than the second angle so the latch moves to the engaged position before the guard reaches the guard pivot point. 
     
     
       4. The brush cutter of  claim 3  wherein the first angle is between about five and twenty-five degrees and the second angle is more than fifty degrees. 
     
     
       5. The brush cutter of  claim 1  wherein the guard includes a guard pivot axis, the latch includes a latch pivot axis, and the housing includes a tilt axis. 
     
     
       6. The brush cutter of  claim 5  wherein the guard further comprises a proximal portion near the guard pivot axis and a distal portion near an outer edge, and the latch is configured to engage the guard at the distal portion. 
     
     
       7. The brush cutter of  claim 5  wherein the tilt axis is parallel to the latch pivot axis. 
     
     
       8. The brush cutter of  claim 5  wherein the tilt axis is perpendicular to the guard pivot axis. 
     
     
       9. The brush cutter of  claim 1  wherein the latch moves between the retracted position and the engaged position by gravity. 
     
     
       10. The brush cutter of  claim 1  wherein the latch moves between the retracted position and the engaged position by an electric or hydraulic motor or solenoid. 
     
     
       11. The brush cutter of  claim 1  wherein the guard includes an opening configured to receive a portion of the latch. 
     
     
       12. The brush cutter of  claim 1  further comprising a hydraulic motor operatively combined with the cutting member to rotate the cutting member relative to the housing. 
     
     
       13. A brush cutter comprising:
 a housing; 
 a cutting member combined with the housing; 
 a motor operatively combined with the cutting member to rotate the cutting member relative to the housing; 
 a guard combined with the housing and configured to pivot about a guard pivot axis, the guard having an open position wherein the cutting member is exposed for cutting operations and a closed position wherein the cutting member is at least partially shielded by the guard, wherein the guard has a guard pivot point; 
 a latch assembly having a latch configured to pivot about a latch pivot axis between a retracted position wherein the guard is movable from the closed position to the open position and an engaged position wherein the latch prevents movement of the guard from the closed position to the open position, wherein the latch has a latch pivot point and is configured to move from the retracted position to the engaged position upon tilting the housing about a tilt axis and beyond the latch pivot point; 
 wherein the latch pivot point is reached upon tilting the housing a first angle relative to a horizontal ground surface and the guard pivot point is reached upon tilting the housing a second angle relative to the horizontal ground surface, wherein the first angle is less than the second angle so the latch moves to the engaged position before the guard reaches the guard pivot point. 
 
     
     
       14. The brush cutter of  claim 13  wherein the first angle is between about five and twenty-five degrees and the second angle is more than fifty degrees. 
     
     
       15. The brush cutter of  claim 13  wherein the latch moves between the retracted position and the engaged position by gravity. 
     
     
       16. The brush cutter of  claim 13  wherein the latch moves between the retracted position and the engaged position by an electric or hydraulic motor or solenoid. 
     
     
       17. The brush cutter of  claim 13  wherein the tilt axis is parallel to the latch pivot axis. 
     
     
       18. The brush cutter of  claim 13  wherein the tilt axis is perpendicular to the guard pivot axis. 
     
     
       19. A method of using a brush cutter comprising:
 taking a brush cutter having a housing, a cutting member combined with the housing, a motor operatively combined with the cutting member, a guard combined with the housing about a guard pivot point and movable between an open position wherein the cutting member is exposed for cutting operations and a closed position wherein the cutting member is at least partially shielded by the guard, and a latch assembly having a latch movable about a latch pivot point between a retracted position wherein the guard is movable from the closed position to the open position and an engaged position wherein the latch prevents movement of the guard from the closed position to the open position; 
 tilting the brush cutter from a first position wherein the latch is in the retracted position to a second position wherein the latch is in the engaged position and the housing is positioned at a first angle relative to a horizontal ground surface; 
 tilting the brush cutter from the second position to a third position wherein the housing is positioned at a second angle relative to a horizontal ground surface which is larger than the first angle, beyond the guard pivot point, and wherein the latch engages the guard and prevents the guard from moving to the open position. 
 
     
     
       20. The method of  claim 19  further comprising tilting the brush cutter back to the first position thereby causing the latch to move from the engaged position to the retracted position. 
     
     
       21. The method of  claim 19  further comprising adding weight to the latch assembly to change the latch pivot point.